New DIN Rail Frequency Input Modules Accept DC-To-100kHz Signals, and Provide 1500Vrms Isolation

Press Release

Release Date: Jan 1 1999
Dataforth Corporation, Tucson, Arizona announces the introduction of its new family of DIN rail mounted DSCA45 frequency-to-voltage/current modules. These modules provide a simple, low cost method for interfacing magnetic-pickups and tachometers from flow meters, engine test stands, rotating equipment, and other pulse or "zero-crossing" signals to data acquisition and control systems for the plant, process, or laboratory.

Each DSCA45 frequency input module provides a single channel of pulse or frequency input, which is isolated and converted to a standard analog voltage or current output. The modules will accept TTL-level or zero-crossing signals in various ranges from 0-500Hz to 0-100kHz and convert them to proportional 0 to +10V, 0 to 20mA, or 4 to 20mA output signals. Input levels may range from 60mVp-p to 350Vp-p, and input hysteresis is provided for each signal type. An excitation source of 5.1Vdc at 8mA maximum is available for use with magnetic pick-up or contact-closure type sensors. Current output models have a built-in dedicated isolated loop supply, which provides an active output signal.

Outputs are isolated to 1500Vrms continuous from "field" side transients and surges, which might otherwise degrade signal integrity and damage expensive "computer" side equipment. The isolation barrier also eliminates troublesome ground loops. Special input circuits provide protection against accidental connection of power-line voltages up to 240Vac and against transient events as defined by ANSI/IEEE C37.90.1-1989. Protection circuits are also present on the signal output and power input terminals to guard against transient events and power reversal. Signal and power lines are secured to the module with pluggable terminal blocks, which allow ease of system assembly and reconfiguration.

Specified accuracy for the DSCA45 is +/-0.05% of span, including nonlinearity, hysteresis, and repeatability. Both zero and span may be adjusted +/-5% from two easily accessible potentiometers on the front of the module. The adjustments are non-interactive for ease of use. Special built-in filters reduce common mode 50Hz and 60Hz noise by 120dB.

The modules will accept wide range power from 19Vdc to 29Vdc with current requirements between 60mA and 80mA, depending if the module is a voltage or current output type. An LED indicator on the front panel is lit when power is connected.

Rated operating temperature range is –40C to +80C, and the relative humidity range is zero to 95% noncondensing. All modules meet the requirements of EN50081-1 (radiated/conducted emissions) and EN50082-1 (ESD/RF/EFT immunity). Case dimensions are 2.95 x 0.89 x 4.13 inches (75mm x 22.5mm x 105mm). The modules may be mounted on standard DIN EN50022-35x7.5 or –35x15 rails.

For additional information and pricing, call 800-444-7644 toll-free, or e-mail at
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